This paper examines the pressure behavior of a horizontal well that isintercepted by several vertical fractures. A mathematical model was developedand used to discern the characteristic responses of a multiply-fracturedhorizontal-well. A systematic discussion of pressure behaviors is given newinterpretations and conclusions are provided. A simple screening guide toevaluate the efficacy of this completion scheme is presented. The consequencesof perforating selective sections after fracturing are examined. The pressurebehaviors that are discussed in this work are used to analyze responses of afield test. This test was conducted on a medium horizontal-well completed in adolomite/anhydrite formation with a 1900'horizontal section. Four distinctintervals were perforated and individually stimulated. Results from theanalysis of the commingled test are presented in this work. The methodologyoutlined here should be useful to others. Practical guidelines areprovided.
This paper presents results based on the following premise: The purpose offracturing horizontal wells is to create a system such that the long-timeperformance of the horizontal well will be equivalent to that of a fracturedwell with a specific conductivity (preferably infinite conductivity) andfracture length equal to distance between the two outermost fractures. Thisperspective is an important departure from studies presented in the literature.We begin this study by presenting new correlations to determine the long-timeperformance of a multiply-fractured, horizontal-well system. This phase of ourwork will be suitable for screening and designing purposes and for predictinglong-time performance either by analytical models or by numerical simulation.As a consequence of the availability of this correlation, exercises similar tothose given in Refs. 1 and 2 can be performed more conveniently andcomprehensively. The second part of this study presents analytical proceduresto evaluate pressure measurements in a multiply-fractured horizontal-well. Acomprehensive and complete evaluation is provided. In the third part of thiswork, we examine a field example that permits the use of the theoreticaldevelopments noted in this work, highlights the measurements that ran behelpful and the improvements that need to be made in our abilities to analyzepressure responses.
